Gas turbine engines, such as those which power aircraft and industrial equipment, employ a compressor to compress air that is drawn into the engine and a turbine to capture energy associated with the combustion of a fuel-air mixture. As one skilled in the art appreciates, it is necessary to maintain various pressures and temperatures in various portions/regions of the engine in order to ensure engine stability and maximize/enhance engine performance/efficiency.
Referring to FIG. 2, a portion of an engine 200 in accordance with the prior art is shown. The engine 200 incorporates a curvic seal 204 that is used to maintain pressure or temperature as described above. A curvic joint 208, which includes curvic teeth, mates/interfaces to a compressor disk 212 of the compressor and a turbine disk 216 of the turbine. The seal 204/joint 208 may provide a centering-feature and transfer of torque as long as a preload in an amount greater than a threshold is maintained.
The seal 204 includes a snap 220 near the aft-most end of the seal 204. The snap 220 allows the seal 204 to engage the turbine disk 216. In contrast to the use of the snap 220, towards the forward end of the seal 204 (in proximity to the location of the reference character 224) a loose fit is provided between the seal 204 and the compressor disk 212. A wire seal 228 is included to counter any leakage 232 (the direction of which is shown in FIG. 2 as flowing from high pressure to low pressure) that might otherwise be experienced due to the loose fit 224. The (axial) proximity of the snap 220 to the joint 208 imparts a hoop stress into the curvic teeth. This stress reduces the useable lifetime of the seal 204.
The engine 200 also includes a balance weight 236. The balance weight 236 accounts for any non-idealities in terms of the orientation of the interface between the joint 208 and the compressor disk 212 or the interface between the joint 208 and the turbine disk 216. As one skilled in the art would appreciate, the non-idealities may be determined based on the use of one or more reference components and one or more algorithms. The algorithms return a result/value that indicates a location on the turbine disk 216 as to where the balance weight 236 should be located. The location of the balance weight 236 is selected so as to be equal in magnitude, but 180 degrees out of phase with, the non-ideality in order to cancel the impact of the non-ideality. While shown in FIG. 2 as attaching to the turbine disk 216, the balance weight 236 may alternatively be attached to the compressor disk 212.